He is mentioned as "Tumen" in the ancient Chinese sources. Little is known about his life, and most of the information depends on legends in which he is known to gather a group of Turkic people living in a legendary place called Ergenikon located on the inaccessible valleys of the Altay Mountains.
He successfully fought against the Avars, another tribe of Turkic people, and eventually founded the Kokturk state, which expanded, in less than one century, to wide territories in Central Asia. He died on the same year he founded his state.